USGS Body-Wave Moment Tensor Solution
SANTA CRUZ ISLANDS
12/09/05 13:09:08.44 Epicenter: -12.510 166.497 MW 5.9 USGS MOMENT TENSOR SOLUTION Depth 19 No. of sta: 67 Moment Tensor; Scale 10**17 Nm Mrr=-7.07 Mtt= 0.37 Mpp= 6.70 Mrt=-3.58 Mrp=-1.75 Mtp=-5.50 Principal axes: T Val= 9.89 Plg= 1 Azm=240 N -0.44 31 149 P -9.45 59 331 Best Double Couple:Mo=9.7*10**17 NP1:Strike=123 Dip=54 Slip=-130 NP2: 357 52 -49
The figure above shows a visual representation of the style of faulting (focal mechanism) derived from the estimated moment tensor. Shaded areas show quadrants of the focal sphere in which the P-wave first-motions are away from the source, and unshaded areas show quadrants in which the P-wave first-motions are toward the source. The dots represent the axis of maximum compressional strain (in black, called the "P-axis") and the axis of maximum extensional strain (in white, called the "T-axis") resulting from the earthquake.